Definitions for additament

Secondly, with an additament, wherein brimstone is approved to help to the melting of iron or steel.Francis Bacon, "Physiological Remains," The Works of Lord Bacon, 1838

But let her stand upon her female character as upon a foundation; and let the attentions incident to individual preference, be so many pretty additaments and ornaments, as many and as fanciful as you please, to that main structure.Charles Lamb, Essays of Ella, 1838